The reaction of alkyl-substituted thioanisoles with PCl3 and AlCl3: a route to [1,2,3]benzothiadiphospholo[2,3-b][1,2,3]benzothiadiphosphole derivatives

Abstract

The synthesis of [1,2,3] benzothiadiphospholo[2,3-b][1,2,3]benzothiadiphosphole derivatives starting from alkyl-substituted thioanisoles and PCl₃–AlCl₃is reported. The reaction is carried out at reflux in the absence of solvent and the yields are dependent on the starting sulphide. These new heterocycles can be purified by simple filtration on a Florisil column and have been characterized by ¹H-, ¹³C-, (¹H)³¹P-n.m.r. and mass spectroscopy analyses. New unexpected findings are also described.